Mechanism for truing and dressing grinding wheels



June 30, 1931. F. J. HOHNHORST ET AL 1 ,9

MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS Filed June 20. 1929 6Sheets-Sheet l June 30, 1931. i F.- J. HOHNHORST ET AL 1,811,933

A MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS I Filed June 20.1929 e Sheets-Sheet 2 June 1931- F. J. HOHNHORST ET AL 1 811,9 3

MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS Filed June 20. 1929 6Sheets-Sheet 3 lNl/E/VTORS June 30, 1931. F. J. HOHNHORST ET AL1,311,933

MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS Filed June 20, 1929 6Sheets-Sheet 4 June 30, 1931. F.- J. HOHNHORST ET AL 1,311,933

MECHANISM FOR TiwINe AND nanssme GRINDING WHEELS Filed-June 20. 1929 sSheets-Sheet 5 June 30, 1931. F. J. HOHNHORST ETAL 1,311,933

MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS Filed June 20. 1929 6Sheets-Sheet 6 Patented June 30, 1931 UNITED STATES FERDINAND J.HOHNHORST ANIJ FERDINAND J. KROEGER, F COVINGTON,

KENTUCKY MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS Applicationfiled June 20.

Our invention relates to mechanism for truing or dressing grindingwheels, such as emery wheels, employed in machinery for grinding orpolishing the surfaces of metal in precision grinding, and is employablefor truing or dressing the grinding wheel without removing the grindingwheel from the grinding or polishing machine, and without removing thework from between the centers in the grinding or polishing machine.

It is the object of our invention to provide novel means whereby tosupport the abrading part in inactive relation and to adjust the sameinto active relation with the grinding wheel; further, to provide novelmeans for mounting the abrading part on the tail-stock of the rindingmachine; further, to provide novel means for adjusting the abrading partabout the axis of the tail-spindle; and, further, to provide novel meansfor fixing the abrading part in adjusted positions and for permittingaxial movements of the tail spindle.

The invention will be further readily understood from the followingdescription and claims, and from the drawings in which latter:

Fig. 1 is a plan view of our improved device applied to an exemplifiedgrinding machine, partly broken away.

2 is a cross-section of the same, taken on the line 22 of Fig. 1, andpartly broken away.

Fig. 3 is a cross-section of a detail of the same, taken on the line 3-3of Fig. 1, and partly broken away.

Fig. 4-. is a side elevation ofour improved device, the grinding machinebeing partly broken away and partly in section.

Fig. 5 is a plan view of the same.

Fig. 6 is a sectional detail of one of the clamping means, taken on theline 6-6 of Fig. 5.

Fig. 7 is a sectional detail of another of the clamp means, taken on theline 77 of Fig. 4.

Fig. 8 is an axial section of our improved device, taken on theirregular line 88 of Fig. 4.

Fig. 9 is a side elevation of a modification 1929. Serial No. 372,416.

of our improved device, the grinding machine being partly broken away.

Fig. 10 is an axial section of thesame. taken in the plane of theirregularline 10-10. of Fig. 9.

ig. 11 is a cross-sectional detail view, taken in the plane of the line11-11 of Fig. 10.

Fig. 1:2 is a side elevation of a second modification of our improveddevice, with the, grinding machine partly broken away.

Fig. 13 is an axial section of the same, taken in the plane of the line1313 of Fig. 12. V I

Fig. l lis a sectional detail view of the same, taken in the plane ofthe line 14-14 of Fig. 13.

Fig. 15 is a cross-sectional detail view of the same, taken in the planeof the line 1515 of Fig. 13. r i

F ig. 16 is a side elevation of a third modification of the same, thegrinding machine being partly broken away; and,

Fig. 17 is an axial section of the taken on the line 17-17 of Fig. 16.

In grinding machines, as usually constructed, axial movement takes placebetween the work and the grinding wheel, either by lengthwise feeding ofthe work-supporting table or by axial feeding of the support for thegrinding wheel. We have exemplified a machine in which the axial feed iscaused by lengthwise movement of the work-supporting table.

Our invention is particularly applicable in connection with machines inwhich it is desired to grind or polish long cylindrical ob} jects, forinstance, shafts of different diameters, and in which it is desired todress the grinding wheel without removing the grinding wheel .or thework from the grinding ma chine. Our improved device is furtherapplicable in such relations where it is desired to dress the grindingwheel at each complete reciprocation between the work and the grind ingwheel.

For accomplishing these objects weprovide a frame on which the abradingpart is same,

supported, this abrading part being eX- emplified as an abrading wheel.Ne furce grinding ther so mount the supporting frame so that theabrading part may be positioned out of the range of movement of thegrinding wheel or adjusted into contact with the grinding wheel, and wehave further pivotally mounted the supporting frame for the abradingpart about the axis of the tail-spindle of the machine in such mannerthat axial adjustments of the tail-spindle are permitted; and, further,so that rigid positioning of the supporting frame may be had.

In the present exempliflcation the grinding machine comprises a frame11, on which there is a slide 12, adjustable in suitable manner upon theframe. This slide is provided with bearings 13 in which a shaft 14 isjournaled, a grinding wheel 15 being suitably releasably secured to theshaft. The grinding wheel is rotated, for instance, by means of asuitable belt passing about a pulley 16 on the shaft 1 1. The grindingwheel is instanced as rotating in the direction of the arrow a.

The grinding wheel may for instance be an emery wheel of suitableconstruction. The grinding surface of the grinding wheel becomesimpregnated with particles of the material being ground and othersubstances. It becomes dull and loses its grinding efl'ect, requiringthat the grinding surface be redressed or resharpened, which in thepresent instance is accomplished by an abrading part, shown as anabrading wheel 17 The abrading wheel is instanced as a normallyquiescent abrading wheel, arranged to be rotated in the direction of thearrow 1) by contact with the rotating grinding wheel.

A saddle 21 is slidable on guideways 22, 23, on the frame, and isfeedable by means of a rack 24, with which a pinion 25, suitably drivenin reverse directions, meshes, for providing suitable endwise feed inreverse directions between the work, exemplified at 26 and the abradingpart 17, on the one hand, and the grinding wheel 15, on the other hand,although this endwise feed may be obtained by endwise movement of thegrinding wheel with relation to the work and the abrading part, asexplained for instance in Patent No. 1,544,985, granted us July 7, 1925,for improvement in mechanism for truing and dressing grinding wheels.

A work-supporting table 31 is pivoted by a pivot 32 on the saddle 21.This work-supporting table has thereon the usual headstock 33 supportingthe usual head-center 34:, and the usual tail-stock 35 supporting theusual tail-center 36, the work 26, exemplified as a shaft of largediameter, being supported in usual manner between said centers. Thehead-center is in the usual quill 37 in a bearing 38 of the head-stock.The quill may be rotated in usual manner, as by means of a usual pulley39 fixed to the quill.

Usual means are provided for causing the work to rotate with thehead-center and with the quill. The head-stock is arranged to bepositioned in usual manner on the table, being slidable laterally onguideways 40, 41, on the table, and suitably clamped in adjustedpositions.

The tail-center 36 is mounted in usual manner in a usual tail-spindle15, adjustable axially in a barrel 16 of the tail-stock, as by means ofa screw 17, which is held endwise in a bearing 48 of the tail-stock andhas a hand-wheel 19 thereon for rotating the same. The tail-spindle isprevented from rotating by being provided with a spline-groove 50, inwhich a key 51 in the bearing 16 is received. A clamp-shoe 52 isslidable in a guideway 53 in the tail-stock. A screw 54 is threaded in athreaded hole 55 in the tailstock and has a handle 56 thereon, whichbears upon the shoe, and by means of which the screw is rocked inopposite directions for respectively clamping and unclamping thetail-spindle in the tail-stock.

The tail-stock is adjustable laterally on the guideways 4:0, 11, of thetable, and is clamped in suitable manner in adjusted positions to thetable.

Referring to Figs. 1 to 8 inclusive, a frame 61 is provided with abearing 62, received about the tail-spindle. The bearing is on anannular flange 60, which extends from the barrel 46 of the tail-spindle.The frame also has a bearing 63, in which an axle 6 1 is secured. Ashell 65 is received about the axle. Ball-bearings 66, 67 are locatedbetween the axle and the shell and are held endwise to the axle. Theabrading wheel 17 is secured to the shell, as between a flange 68 on theshell at one side of the abrading wheel, and a collar 69 about the shelland a nut 7 0 threaded about the threaded end of the shell at the otherside of the abrading wheel. The abrading wheel is thus rotativelymounted upon the frame 61. This frame may be termed a quadrant frame. Ashield 59 is provided on the frame for the abrading wheel.

The abrading part may be of other form and other mountings may beemployed within the spirit of my invention, as contained in theaccompanying claims.

Clamping means 76 are provided between the pivoted frame and thetail-stock. These are shown comprising a stud 77 having a threaded end78 threaded into a threaded hole 79 in the tail-stock. This stud has aflange 80, forming a shoulder, for coaction with the inner end face ofthe tail-stock. The threaded portion 81 of the stud is received throughan arcuate slot 82 in the pivoted frame 61. This arcuate slot is formedabout the bearing 62, and is preferably on an are which has the axis ofthis hearing as its center. The flange 80 has flattened portions 75.

The arcuate portion 83 of the pivoted frame is located between a nut 84on the threaded portion 81 of the stud at one side of the pivoted frame,and a washer 85 and a nut 86 about said threaded portion 81 at the otherside of the frame. The nut 8 1 is provided with a set-screw 8? forclamping the nut to the stud. This nut 84 is preferably placed in suchposition on the stud that the arcuate portion of the plate 61 issupported thereby when the bearing 62 is on the flange 60 and the outerend of said bearing is supported by the inner end of the barrel 16 ofthe tail-spindle.

The nut 86 is arranged to clamp the pivoted plate to the tail-stock inthe various positions of the pivoted plate.

A handle 88 is on the pivoted plate, by means of which the pivoted plateis manipulated for rocking the same about the tailspindle andposltioning-the abrading part either in inactiverelation, away from thepath of the grinding wheel, or in proper abrading relation with thegrinding wheel for performing the abrading operation.

A releasable clamp 91 is provided for clamping the pivoted frame aboutthe flange 60. This is shown as comprising a clampshoe 92, movable in aguideway 93 in the pivoted frame. A bolt 94 has threaded con nection 95at the inner end of said guideway, for fixing the bolt to the pivotedframe. A spring 96 is received in the guideway between the. end wall 97of said guideway and the shoe, for normally pressing the shoe outwardlyaway from the tail-spindle.

A nut 98 threaded about the bolt coacts withthe shoe for forcing theshoe inwardly against the flange 60, and thereby clamping the pivotedframe about the tail-spindle, or for relieving inward pressure on theshoe, so that the shoe may be pressed outwardly by the spring 96, forreleasing its clamping pressure upon the flange, in order that axialmovement of the tail-spindle may take place. Release relation of theshoe also permits pivotal movement of the frame to take place uponrelease of the clamping means 76.

In employing our improved device, the pivoted frame 61 may be adjustedinto such position that the abrading wheel 17 is out of range of thepath of the grinding-wheel 15. The abrading wheel is shown arranged tomake contact with the grinding-wheel be low the horizontal plane inwhich the axis of the grinding-wheel is located. The abrading wheel istherefore adjusted downwardly and outwardly to be out of range of thegrinding-wheel. The pivoted frame is clamped in such inactive relationby the clamping means 76. The releasable clamp 91 of the tail-spindlemay in such position be in release relation.

When it is desired to place the abrading wheel in active relation, theclamping means 76 are released, whereupon the pivoted frame is rotatedabout the tail-spindle, for placing the periphery of the abrading wheelinto contact position with the periphery of the grinding Wheel, theclamping means 76 being thereupon clamped, and the releasable clamp 91being also preferably clamped about the tail-spindle, so as to provide arigid support for the abrading wheel while in operative position,thereby preventing chattering or unequal rotation of the abrading wheelduring the abrading operation.

The clamp 91 may be maintained in such a frictional engagement about theflange 60 as to permit rotation of the pivoted frame 61 upon release ofthe clamp 76, the clamp 91 being maintained sufficiently tight to insuresteady operation of the abrading wheel.

The abrading Wheel may, if desired, re-

main in such active relation during the grinding operation, forcontact-between the abrading wheel and the grinding-Wheel at the end ofeach complete reciprocation of the work,

for maintaining the grinding-wheel in dressed relation. If desired,however, the abrading wheel may be placed in such active position onlyduring intervals of dressing action upon the grinding wheel, obtained byshort reciprocations of the abrading Wheel in contact with thegrinding-wheel beyond one end of the work. Either of these uses of theabrading wheel may, however, take place without disturbing the work andthe grinding adjustment between the grinding-wheel and the work. 1

If it is desired to adjust the tail-spindle endwise, this may beaccomplished without disturbing the position of the abrading wheel.

The bearing 62 is preferably provided with anannular flange 99, inwardlyof the inner ion end of the flange 60. The inner periphery of thisflange rides upon the inner portion of the tail-spindle, and forms adust-arresting cap for the tail-spindle.

-A modification of our improved device is shown in Figs. 9, 10 and 11,in which similar parts are designated by similar reference numeralsraised to the series 100.

In this modification, the pivoted frame 161 is provided with a bearing162 about the an nular flange. which extends from the barrel 146 of thetail-stock. In some grinding machines this flange 160 is rather short,and the present modification is accommodated to such conditions.

To form a releasable clamp 191, the bearing 162 is shown as aclamp-bearing being provided with a split 192. A bolt 194 is receivedthrough a hole in the cheek 193 of the hearing at one side of the splitand is threaded in a threadedhole 195 in the cheek 196 of the bearing atthe other side of the split. .By rotating" the bolt the split-bearing162 is either clamped upon the flange 160, or un ing means 176, 191.

The clamping means 191 may be normally maintained sufliciently tight topermit rotation of the pivoted frame 161 and insure steadiness ofoperation.

In this modification a dust-cap 197 is fixed to the end of thetail-spindle 145 by means of screws 198. This dust-cap is provided witha flange 199 slidable endwise in the bore 200 of the pivoted or quadrantframe. This dust-cap is arranged to arrest the dust and dirt i1 cidentto the grinding operation and to protect the tail-spindle and itsbearing therefrom. The limited endwise movement of the tail-spindlerequired in a grinding machine is permitted while the dust-cap or aportion thereof remains in said bore.

A further modification of our invention is exemplified in Figs. 12, 13,14:, and 15, similar parts being designated by similar numerals raisedto the series 200.

In this modification, the pivoted frame 261 is pivoted on a bushing 25?of a bushing-plate 258. -.his bushing-plate is provided with a clampingmeans 201, comprising a clamp bearing 202 provided with a split 203. Abolt 204i is rotatable in a hole in the cheek 205 of the bearing 202 atone side of the split and is threaded in a threaded hole 206 in thecheek 207 of the bearing at the other side of the split, for clampingthe bushing-plate to the annular flange on the barrel 2&6 of thetail-stock, or for releasing said bushing-plate from said flange.

In'this modification, the bushing-plate is provided with thequadrant-slot 282, and the pivoted frame 261 is provided with a hole 211in registry with said slot, a belt 212 being receiv d through said slotand said hole. A nut 213 is arranged to clamp the pivoted frame and thebushing-plate together. Clamping means 27 6 are thus exemplified.

The pivoted frame is also clamped to the bushing by a releasable clamp291. This clamp is in the form of a bearing 262 received about thebushing and provided with a split 292. A bolt 29s is rotatable in a hole111 the cheek 293 at one side of the slit, and is threaded in a threadedhole 295 in the cheek 296 at the other side of said split. Rotation ofthe bolt clamps the split-bearing 262 upon the bushing, or releases thepivoted frame therefrom, so as to permit rotation of the pivoted frameabout the bushing, by manipulation of the handle 28S upon release of theclamping means 276, 291, for positioning the abrading part into contactor out of contact with the grinding wheel. The clamping means 201 or 291may be normally maintained suflioiently tight to permit rotation butinsure steadiness of operation.

A still further modification is shown in Figs. 16 and 17, for adaptingour improved device to grinding machines in which an extremely shortdust-cap flange 360 is present. In this modification, the clamping means391 are transferred from clamping upon the flange, to clamping upon thetail-spindle direct. In this form clamping means 37 6 and 391 areprovided which are the same as the clamping means 7 6 and 91 exemplifiedin Figs. 4; to 8 inclusive. The parts in this modification which aresimilar to the parts previously described are designated by similarreference numerals raised to the series 300.

lVhen employing this modification, the clamping means 391 is unclampedwhen axial adjustment of the tail-spindle is to be made. The bearing362, however, remains in position about the tail-spindle during axialmovement of the tail-spindle, and the abrading wheel is held in fixedrelation'to the tailstock during such axial movement of the tailspindleby the clamped relation of the releasable clamp 37 6. After suchadjustment of the tail-spindle, the clamp 391 is again clamped upon thetail-spindle, insuring rigidity of all the parts.

If it is desired to make angular adjustment of the abrading tool, theclamping means 376, 391, are released, the pivoted frame 361 isadjusted, and the clamping means 3'76, 391, again clamped.

In this modification the pivoted frame is provided with an annularflange 315 received about the flange 360, the structure forming adust-cap for the tail-spindle.

Having thus fully described our invention, what we claim as new, anddesire to secure by Letters Patent, is:

1. In a machine of the character described. the combination with thegrinding wheel, the tail-stock and the tail-spindle, of a pivoted framecomprising a pivot-bearing arranged to be received pivotwise about saidtail-spindle, an abrading part on said pivoted frame arranged forcoaction with said grinding wheel, and releasable arcuate clamping meansbetween said tail-stock and said pivoted frame comprising a clamp-studand an arcuate slot for said clamp-stud, permitting adjustments of saidpivoted frame about said tail-spindle for positional relations betweensaid abrading part and said grinding wheel and arranged for clampingsaid pivoted frame in adjusted positions about said tail-spindle.

2. In a machine of the character described, the combination with thegrinding wheel, the tail-stock and the tail-spindle, of a pivoted framecomprising a pivot-bearing arranged to be received pivotwise about saidtail-spindle, an abrading part on said pivoted frame arranged forcoaotion with said grinding wheel, a clamp-stud arranged for attachmentto said tail-stock, said pivoted frame provided with an arcuate slot forsaid clampstud permitting adustments of said pivoted frame about saidtail-spindle for positional relations between said abrading part andsaid grinding wheel, and arranged for clampfob its

ing said pivoted frame in adjusted positions about said tail-spindle,and a releasable clamp about said tail-spindle permitting axialadjustments of said tail-spindle in said pivotbearing.

3. In a machine of the character described, the combination with therotary grinding wheel, the tail-stock and the tail-spindle, of a pivotedframe comprising a pivot-bearing about said tail-spindle, a clamp'forsaid pivotbearing for clamping said pivoted frame about saidt-ail-spindle, an abrading part on said pivoted frame, a clamp-stud onsaid tailstock, said pivoted frame provided with an arcuate slot inwhich said clamp-stud is located, clamping means for said clamp-stud forclamping said pivoted frame in adjusted positions about saidtail-spindle, and a handle on said pivoted frame wherewith to move saidpivoted frame about said tail-spindle.

4. In a machine of the character described, the combination with therotary grinding wheel, the tail-stock and the tail-spindle, of a pivotedframe comprising a pivot-bearing about said tail-spindle, a bearing onsaid pivoted frame, an abrading wheel supported by said last-namedbearing, a clamp-stud extending from said tail-stock, said pivoted framehaving an arcuate slot about said tailspindle in which said clamp-studis located, and clamping means for said clamp-stud, said pivoted frameadjustable about said tailspindle for positional relation of saidabrading wheel with said grinding wheel, and said clamping meansarranged for clamping said pivoted frame in adjusted positions.

5. In a machine of the character described, the combination with therotary grinding wheel, the tail-stock and the tail-spindle, of a pivotedframe comprising a pivot-bearing about said tail-spindle, a bearing onsaid pivoted frame, an abrading wheel supported by said last-namedbearing, a clamp-stud eX- tending from said tail-stock, said pivotedframe having an arcuate slot about said tailspindle, said clamp-studlocated in said arcu ate slot, clamping means for said clamp-stud,

said pivoted frame adjustable about said tailspindle for positionalrelation of said abrad- 1ng wheel with said grinding wheel, saidclamping means arranged for clamping said pivoted frame in adjustedpositions, and a releasable clamp on said pivoted frame for sandpivot-bearing, said releasable clamp acting to clamp toward saidtail-spindle, and arranged so that said pivoted frame is held axially tosaid tail-stock and said tail-spindle is axially adjustable in saidpivot-bearing.

6. In a machine of the character described, the combination withthegrinding wheel, the tail-stock and tail-spindle, said tail-stockprovided with an inwardly extending annular flange about saidtail-spindle, a pivoted frame about said annular flange, an abradingpart on said pivoted frame arranged to coact With said grinding wheel,radial clamping means on said pivoted frame about said tallspindle, andarcuate clamping means between said pivoted frame and said tall-stock.

In testimony whereof, we have hereunto signed our names.

FERDINAND J. HOHNHORST. FERDINAND J. KROEGER.

